The present invention relates generally to medical catheters, such as gastrostomy feeding tubes, and relates more particularly to low profile adaptors well-suited for use with medical catheters.
Certain patients are unable to take food and/or medications transorally due to an inability to swallow. Such an inability to swallow may be due to a variety of reasons, such as esophageal cancer, neurological impairment and the like. Although the intravenous administration of food and/or medications to such patients may be a viable short-term approach, it is not well-suited for the long-term. Accordingly, the most common approach to the long-term feeding of such patients involves gastrostomy, i.e., the creation of a feeding tract or stoma between the stomach and the upper abdominal wall. Feeding is then typically performed by administering food through a feeding tube that has been inserted into the feeding tract, with the distal end of the feeding tube extending into the stomach and being retained therein by an internal anchor or bolster and the proximal end of the feeding tube extending through the abdominal wall.
Although gastrostomies were first performed surgically, most gastrostomies are now performed using percutaneous endoscopy. In one type of percutaneous endoscopic gastrostomy (PEG) technique, the distal end of an endoscope is inserted into a patient""s mouth and is passed through the esophagus into the stomach. After distension of the stomach by inflation, an entry site on the abdomen is identified and an incision can be made. A needle, with an outer cannula, is inserted through the entry site across the abdominal and gastric walls. While keeping the cannula in place, the needle is removed, and a flexible wire is passed through the cannula into the stomach and into a snare loop extended from the distal end of the endoscope. The endoscopic snare loop is then used to grasp the wire, the cannula is released, and the endoscope and wire are withdrawn through the esophagus and mouth of the patient. A silicone gastrostomy feeding tube, the distal end of which is attached to a silicone, dome-shaped internal bolster, is then secured to the wire and is pulled from its proximal end through the esophagus and into the stomach until the internal bolster engages the stomach wall and the feeding tube extends through the stomach and abdominal walls, with the proximal end of the feeding tube extending approximately one foot beyond the abdominal wall. (Over a period of several days following implantation of the feeding tube, a stable stoma tract forms around the feeding tube between the gastric and abdominal walls.)
With the internal bolster in place against the gastric wall, an external bolster is typically secured to the feeding tube to engage the abdomen so as to prevent longitudinal movement of the feeding tube within the stoma tract Additionally, a xe2x80x9cY-portxe2x80x9d adapter is typically attached to the proximal end of the feeding tube, the Y-port adapter being adapted to receive a pair of connector tips through which food and/or medications may be dispensed. In addition, a detachable locking clip is typically secured to the feeding tube at a point between the external bolster and the Y-port adapter to prevent gastric fluids from escaping through the proximal end of the feeding tube when the feeding tube is not in use.
Alternative techniques for implanting gastrostomy feeding tubes using percutaneous endoscopic gastrostomy are disclosed in U.S. Pat. No. 5,112,310, inventor Grobe, which issued May 12, 1992, and U.S. Pat. No. 5,167,627, inventors Clegg et al., which issued Dec. 1, 1992, both of which are incorporated herein by reference.
Although gastrostomy feeding tubes of the type described above work well for their intended purpose, many active patients find the nearly one foot length of tubing that extends externally to be unwieldy, difficult to conceal and susceptible to being inadvertently pulled on. As can readily be appreciated, these conditions are potential sources of physical and/or psychological trauma to the patient. Consequently, a variety of low-profile replacement tube assemblies (also referred to in the art as low-profile replacement PEG devices) have been designed for implantation within the stoma tract following the removal of an initially-implanted gastrostomy feeding tube. Such replacement assemblies are referred to as being xe2x80x9clow-profilexe2x80x9d because they are considerably more compact externally than the above-described initially-implanted gastrostomy feeding tube assemblies.
An example of a low-profile replacement PEG device is disclosed in U.S. Pat. No. 4,944,732, inventor Russo, which issued Jul. 31, 1990, and which is incorporated herein by reference. The low-profile replacement PEG device of said patent comprises a deformable, conical tip portion having at least one side aperture therethrough, a tube portion which extends rearwardly from the tip portion, a fitting portion on the rear end of the tube portion, a removable valve portion in the fitting portion and a flange portion which extends outwardly from the fitting portion. The device is adapted to be installed in a patient so that the tube portion extends through a pre-established stoma with the tip portion located in the patient""s stomach and with the fitting portion and the flange portion engaging the skin of the patient adjacent the stoma
The deformable tip portion of the above-described low-profile replacement PEG device functions as an internal bolster to anchor its associated tube portion in a patient""s stomach. To implant and/or remove the aforementioned tube portion from a patient""s stomach, an obturator or similar device is typically inserted through the tube portion and is used to elongate or otherwise deform the tip portion in such a way as to permit the tip portion to fit through the stoma. Removal of the obturator from the tip portion then permits the tip portion to expand to its original shape for anchoring.
Another type of low-profile replacement PEG device uses an inflatable balloon, instead of a deformable tip portion, as an internal bolster to retain the distal end of its associated tube within a patient""s stomach. To implant such a device in a patient, the inflatable balloon is deflated, the distal end of the tube portion is inserted through the stoma, and the balloon is then inflated. To remove the implanted device from a patient, the balloon is deflated and the tube is then withdrawn from the stoma
Further examples of low-profile replacement PEG devices are disclosed in U.S. Pat. No. 4,863,438, inventors Gauderer et al., which issued Sep. 5, 1989; and U.S. Pat. No. 5,720,734, inventors Copenhaver et al., which issued Feb. 24, 1998, both of which are incorporated herein by reference.
Although low-profile replacement PEG devices are less awkward and bulky than initially-implanted gastrostomy tube assemblies, the use of such low-profile replacement PEG devices suffers from its own set of shortcomings. One such shortcoming is that the implantation of a low-profile replacement PEG device must be preceded by the removal of an intially-implanted gastrostomy tube. Such removal typically involves pulling on the proximal end of the gastrostomy tube until the internal bolster fails and is drawn through the stoma. As can readily be appreciated, such a procedure can be quite painful to the patient and can result in damage to the stoma, thereby delaying when the replacement device can be implanted.
Another shortcoming of many low-profile replacement PEG devices is that such devices typically do not last as long as initially-implanted gastrostomy tube assemblies (most commonly due to failure of their internal anchoring mechanisms or due to clogging or other failure of their valve mechanisms) and, therefore, must be replaced more frequently than is the case with initially-implanted gastrostomy tube assemblies.
Still another shortcoming of many low-profile replacement PEG devices is that such devices are typically not adjustable in length. This can be problematic because there is often an appreciable variation in stoma length from patient to patient. Consequently, it is typically necessary, after removal of the initially-implanted tube and prior to implantation of the replacement device, to measure the length of the stoma and then to select a replacement device having an appropriate length. As can readily be appreciated, this approach requires that there be made available an inventory of replacement devices of varying lengths.
In order to avoid the aforementioned shortcomings of low-profile replacement PEG devices while, at the same time, avoiding the above-described problems associated with having a gastrostomy tube extend externally for a substantial length, there have recently been devised a number of adaptors designed for use in converting an initally-implanted gastrostomy tube into a low-profile PEG device. One such adaptor is disclosed in U.S. Pat. No. 5,549,657, inventors Stern et al., which issued Aug. 27, 1996, and which is incorporated herein by reference. According to said patent, an adaptor is disclosed therein that is designed for use with a gastostomy feeding tube which has been inserted by means of conventional endsocopic procedures and which has been cut to a desired length by a surgeon. The adaptor is said to comprise an anti-reflux valve assembly having a stem which can be plugged into the open end of the feeding tube. The valve assembly is said to contain a seal which functions as a one-way valve to prevent reflux of gastric contents but which permits the introduction of feeding solution into the feeding tube. A clamp is placed around the feeding tube and the valve stem and is locked into place to secure the valve assembly to the feeding tube at a location flush with the patient""s skin. A silicone cover is placed around the clamp to protect the patient from skin irritation caused by the clamp and also to protect the clamp and valve assembly from contaminants.
Although the aforementioned adaptor favorably addresses some of the problems discussed above, the present inventors have identified certain shortcomings associated therewith. One such shortcoming is that the clamp of said adaptor is quite small and, therefore, is difficult to manipulate. Moreover, to insert the valve stem down into the gastrostomy feeding tube and then to attach the clamp around the gastrostomy tube against the valve stem, one must allow for a sufficient externally-extending length to be left in the gastostomy tube so that one can grasp the gastrostomy tube at a point distal to where the valve stem and the clamp are coupled to the tube. (Otherwise, the gastrostomy tube may be pushed completely into the patient, for example, as the valve stem is pushed down into the tube.) This extra length of externally-disposed tubing, however, precludes the clamp from resting flush against the patient when the internal bolster is flush against the stomach. Consequently, either the adaptor is positioned a short distance from the skin, thereby rendering it higher in profile than it otherwise would be, or the distal end of the tube extends a short distance into the stomach, possibly interfering with stomach function.
Another shortcoming is that the clamp has a tendency to pinch the proximal end of the gastrostomy tube at those points where the male and female sections of the clamp are joined. Such pinching, over time, has a tendency to cause the tube to tear. In addition, once the clamp is closed, it cannot be re-opened; consequently, one cannot remove and re-attach the valve stem and the clamp from the proximal end of the gastrostomy feeding tube. Accordingly, once the clamp has been closed, one cannot adjust the length of the gastrostomy feeding tube nor can one clean the valve stem or the proximal end of the feeding tube to remove any accumulated debris therewithin. Moreover, one cannot simply eliminate the clamp from the aforementioned adaptor since, in the absence of the clamp, the valve stem, which has a barb-type fitting, can rather easily be pulled out of the feeding tube (i.e., with about a 5 pound pulling force).
Still another shortcoming with the aforementioned adaptor is that the valve assembly of the subject adaptor relies upon the use of a silicone gasket having a Y-shaped slot through which a cannula is typically inserted to deliver food and/or medications. However, such a silicone gasket, after repeated insertions of the cannula therethrough, has a tendency to tear or to otherwise fail to act reliably as a one-way valve. Consequently, because the adaptor cannot easily be disconnected from the gastrostomy feeding tube once connected thereto, replacement of a worn gasket requires the removal and replacement of the gastrostomy feeding tube as well.
Still yet another shortcoming with the aforementioned adaptor is that it possesses a relatively small lumen through which fluid may pass. In addition, due to its manner of operation, the valve tends to get clogged over time, further restricting fluid flow.
It is an object of the present invention to provide a novel low profile adaptor designed for use with a medical catheter, such as a gastrostomy feeding tube.
It is another object of the present invention to provide a low profile adaptor as described above that overcomes at least some of the problems described above in connection with existing PEG devices, in general, and low profile PEG devices, in particular.
Therefore, according to one aspect of the invention, there is provided a low profile adaptor well-suited for use with a medical catheter, such as a gastrostomy feeding tube, said adaptor comprising (a) a sleeve, said sleeve having a longitudinal bore up through which the proximal end of the medical catheter may be inserted; (b) means for securing the medical catheter to said sleeve; and (c) means for alternately opening and closing the medical catheter to the passage of fluid therethrough.
In a preferred embodiment, the adaptor comprises a body, a clamp and a cap. The body includes a base portion and a sleeve portion, the base portion being dimensioned to engage the skin of a patient and having a transverse bore, the sleeve portion extending upwardly from the base portion and having a longitudinal slot aligned with the transverse bore and a transverse slot intersecting the longitudinal bore. The clamp, which is slidably mounted on the base portion and across the transverse slot of the sleeve, comprises a plate having a transverse opening. The transverse opening has a wide region alignable with the longitudinal bore and correspondingly dimensioned and a narrow region also alignable with the longitudinal bore. In use, a medical catheter is inserted up through the base portion and the sleeve portion, including up through the transverse opening of the clamp situated within the sleeve, and is then inverted over the top edge of the sleeve and across a barb formed on the exterior of the sleeve. The cap is then threadingly mounted on top of the sleeve so as to secure the inverted end of the catheter to the exterior of the sleeve. The cap is provided with an opening through which access to the catheter may be gained. By aligning the wide region or the narrow region of the clamp with the longitudinal bore of the sleeve, one can open or close, respectively, the catheter to the passage of fluids therethrough.
According to another aspect of the invention, there is provided a low profile adaptor well-suited for use with a medical catheter, the medical catheter having a proximal end, said adaptor comprising (a) a body, said body having a base and a sleeve, said base having a transverse bore, said sleeve extending upwardly from said base and having a longitudinal bore and a transverse slot, said longitudinal bore being aligned with said transverse bore of said base, said transverse slot intersecting said longitudinal bore, said transverse bore of said base and said sleeve being appropriately dimensioned to permit a medical catheter to be inserted up through said transverse bore of said base and said longitudinal bore of said sleeve and then inverted over the top of said sleeve; (b) a clamp mounted on said base and movable within said transverse slot between a first position in which said clamp transversely compresses to closure the medical catheter and a second position in which said clamp does not transversely compress the medical catheter, and (c) means for securing the inverted proximal end of a medical catheter to said sleeve.
The present invention is also directed to combinations of the adaptors described above and medical catheters, such as gastrostomy feeding tubes, secured thereto.
According to still another aspect of the invention, there is provided a method of externally bolstering the proximal end of an implanted medical catheter to a patient, said method comprising the steps of (a) providing a body, said body having a base portion and a sleeve portion, said base portion being dimensioned to engage the patient and having a transverse bore, said sleeve portion extending upwardly from said base and, having a longitudinal bore and a top edge, said longitudinal bore being aligned with said transverse bore; (b) inserting the proximal end of the implanted medical catheter up through said transverse bore of said base and said longitudinal bore of said sleeve; and (c) inverting the proximal end of the implanted medical catheter over the top edge of the sleeve onto the exterior of the sleeve.
As can readily be appreciated, although the adaptors discussed above are described as being low profile adaptors, such adaptors are also suitable for use with medical catheters, such as gastrostomy feeding tubes, that extend externally for several inches. Accordingly, the adaptors of the present invention are not limited to being low profile adaptors.
For purposes of the present specification and claims, relational terms like xe2x80x9ctop,xe2x80x9d xe2x80x9cbottom,xe2x80x9d xe2x80x9cupper,xe2x80x9d and xe2x80x9clowerxe2x80x9d are used to describe the present invention in an context in which the invention is secured to a catheter extending upwardly out of a patient. It is to be understood that, by orienting a patient such that the catheter extends outwardly in a direction other than upwardly, the directionality of the invention will need to be adjusted accordingly.
Additional objects, as well as features and advantages, of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. In the description, reference is made to the accompanying drawings which form a part thereof and in which is shown by way of illustration various embodiments for practicing the invention. The embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural changes may be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.